1 /*
2  * Copyright (C) 2009 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <stdio.h>
18 #include <unistd.h>
19 #include <stdlib.h>
20 #include <string.h>
21 
22 #include "edify/expr.h"
23 #include "updater.h"
24 #include "install.h"
25 #include "blockimg.h"
26 #include "minzip/Zip.h"
27 #include "minzip/SysUtil.h"
28 
29 // Generated by the makefile, this function defines the
30 // RegisterDeviceExtensions() function, which calls all the
31 // registration functions for device-specific extensions.
32 #include "register.inc"
33 
34 // Where in the package we expect to find the edify script to execute.
35 // (Note it's "updateR-script", not the older "update-script".)
36 #define SCRIPT_NAME "META-INF/com/google/android/updater-script"
37 
38 struct selabel_handle *sehandle;
39 
main(int argc,char ** argv)40 int main(int argc, char** argv) {
41     // Various things log information to stdout or stderr more or less
42     // at random (though we've tried to standardize on stdout).  The
43     // log file makes more sense if buffering is turned off so things
44     // appear in the right order.
45     setbuf(stdout, NULL);
46     setbuf(stderr, NULL);
47 
48     if (argc != 4) {
49         printf("unexpected number of arguments (%d)\n", argc);
50         return 1;
51     }
52 
53     char* version = argv[1];
54     if ((version[0] != '1' && version[0] != '2' && version[0] != '3') ||
55         version[1] != '\0') {
56         // We support version 1, 2, or 3.
57         printf("wrong updater binary API; expected 1, 2, or 3; "
58                         "got %s\n",
59                 argv[1]);
60         return 2;
61     }
62 
63     // Set up the pipe for sending commands back to the parent process.
64 
65     int fd = atoi(argv[2]);
66     FILE* cmd_pipe = fdopen(fd, "wb");
67     setlinebuf(cmd_pipe);
68 
69     // Extract the script from the package.
70 
71     const char* package_filename = argv[3];
72     MemMapping map;
73     if (sysMapFile(package_filename, &map) != 0) {
74         printf("failed to map package %s\n", argv[3]);
75         return 3;
76     }
77     ZipArchive za;
78     int err;
79     err = mzOpenZipArchive(map.addr, map.length, &za);
80     if (err != 0) {
81         printf("failed to open package %s: %s\n",
82                argv[3], strerror(err));
83         return 3;
84     }
85 
86     const ZipEntry* script_entry = mzFindZipEntry(&za, SCRIPT_NAME);
87     if (script_entry == NULL) {
88         printf("failed to find %s in %s\n", SCRIPT_NAME, package_filename);
89         return 4;
90     }
91 
92     char* script = malloc(script_entry->uncompLen+1);
93     if (!mzReadZipEntry(&za, script_entry, script, script_entry->uncompLen)) {
94         printf("failed to read script from package\n");
95         return 5;
96     }
97     script[script_entry->uncompLen] = '\0';
98 
99     // Configure edify's functions.
100 
101     RegisterBuiltins();
102     RegisterInstallFunctions();
103     RegisterBlockImageFunctions();
104     RegisterDeviceExtensions();
105     FinishRegistration();
106 
107     // Parse the script.
108 
109     Expr* root;
110     int error_count = 0;
111     int error = parse_string(script, &root, &error_count);
112     if (error != 0 || error_count > 0) {
113         printf("%d parse errors\n", error_count);
114         return 6;
115     }
116 
117     struct selinux_opt seopts[] = {
118       { SELABEL_OPT_PATH, "/file_contexts" }
119     };
120 
121     sehandle = selabel_open(SELABEL_CTX_FILE, seopts, 1);
122 
123     if (!sehandle) {
124         fprintf(cmd_pipe, "ui_print Warning: No file_contexts\n");
125     }
126 
127     // Evaluate the parsed script.
128 
129     UpdaterInfo updater_info;
130     updater_info.cmd_pipe = cmd_pipe;
131     updater_info.package_zip = &za;
132     updater_info.version = atoi(version);
133     updater_info.package_zip_addr = map.addr;
134     updater_info.package_zip_len = map.length;
135 
136     State state;
137     state.cookie = &updater_info;
138     state.script = script;
139     state.errmsg = NULL;
140 
141     char* result = Evaluate(&state, root);
142     if (result == NULL) {
143         if (state.errmsg == NULL) {
144             printf("script aborted (no error message)\n");
145             fprintf(cmd_pipe, "ui_print script aborted (no error message)\n");
146         } else {
147             printf("script aborted: %s\n", state.errmsg);
148             char* line = strtok(state.errmsg, "\n");
149             while (line) {
150                 fprintf(cmd_pipe, "ui_print %s\n", line);
151                 line = strtok(NULL, "\n");
152             }
153             fprintf(cmd_pipe, "ui_print\n");
154         }
155         free(state.errmsg);
156         return 7;
157     } else {
158         fprintf(cmd_pipe, "ui_print script succeeded: result was [%s]\n", result);
159         free(result);
160     }
161 
162     if (updater_info.package_zip) {
163         mzCloseZipArchive(updater_info.package_zip);
164     }
165     sysReleaseMap(&map);
166     free(script);
167 
168     return 0;
169 }
170